JP2002075379A - Lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead-acid battery reducing the decrease in the cross section of a continuous cast grid body by the corrosion and improving the battery characteristics. SOLUTION: The cross-sectional shape of an inner bone of the continuous cast grid body is set to a trapezoid having its upper bottom in a mold side. Therefore, even if each vertex part of the grid body is corroded, the cross section in the central part functioned as a collector becomes larger than the conventional one so as to improve the battery characteristics. The trapezoid forming the cross section of the inner bone of the continuous cast grid body is set to such a shape that the inscribed circle becomes the maximum in the same cross section so that, even if each vertex part of the cross section of the inner bone of the continuous cast grid body is corroded, the cross section of the central part functioned as the collector becomes further larger so as to improve the battery characteristics. The cross-sectional bottom of the trapezoid forming the cross-sectional shape of the inner bone of the continuous cast grid body is set to 750 or less, the rapid increase in the bending quantity of the grid body in releasing the mold is eliminated so as to reduce the fraction defective.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a lead-acid battery,
In particular, it relates to the improvement of the inner bone of the continuous casting lattice.

[0002]

2. Description of the Related Art The cross-sectional shape of the inner bone of a continuous cast lattice used in the electrode plate of a conventional lead-acid battery has been a triangle having a vertex on the mold side. In this shape, the contact area between the casting and the mold is reduced, so that the casting is easily separated from the mold and the productivity can be improved.

[0003]

However, in a continuous cast lattice having a triangular cross-section of the inner bone, a corroded layer generated by corrosion is broken at each apex portion, and an electrolytic solution penetrates into that portion. There is a problem that corrosion is promoted and the cross-sectional area functioning as a current collector is reduced.

[0004] It is an object of the present invention to provide a lead-acid battery in which the cross-sectional area of a continuous cast grid that functions as a current collector due to corrosion is reduced and battery characteristics are improved.

[0005]

SUMMARY OF THE INVENTION The present invention is to improve a lead-acid battery using an electrode plate in which a continuous cast grid is filled with an active material.

The lead storage battery of the present invention is characterized in that the cross-sectional shape of the inner bone of the continuous cast lattice is a trapezoid having an upper bottom on the mold side.

[0007] When the cross-sectional shape of the inner bone of the continuous cast lattice is trapezoidal, the cross-sectional area of the central portion functioning as a current collector becomes larger than that of the conventional one even if each vertex is corroded. Battery characteristics can be improved.

Further, in the lead storage battery of the present invention, the trapezoid which forms the cross-sectional shape of the inner bone of the continuous cast lattice is characterized in that the inscribed circle is maximized with the same cross-sectional area.

In this way, even if each of the apexes of the cross section of the inner bone of the continuous cast lattice is corroded, the cross-sectional area of the central portion functioning as a current collector is further increased, and the battery characteristics are improved. be able to.

[0010] In the lead storage battery of the present invention, the trapezoidal cross-sectional base angle of the inner bone of the continuous cast lattice has a cross-sectional base angle of 75 °.
It is characterized by the following.

[0011] If the cross-sectional base angle of the trapezoid forming the cross-sectional shape of the inner bone of the continuous cast lattice becomes larger than 75 °, the amount of bending of the lattice at the time of mold release sharply increases, and the defect rate increases. When the cross-sectional bottom angle is set to 75 ° or less, the amount of bending of the lattice body at the time of mold release does not increase sharply, and the defective rate can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a lead storage battery according to the present invention will be described below in comparison with a conventional example.

The inner bone of the continuous cast lattice used in the lead-acid battery of the present invention has a composition of 1.5 mass% of Pb-Sb.
To e. In order to evaluate the productivity in this example, evaluation was made using the mold releasability from the mold. As an evaluation method, the amount of lattice bending at the time of release was measured (n = 30).

FIG. 2 shows the average value of the cross-sectional base angle and the amount of lattice bending of the inner bone of the continuous casting lattice. As a result, when the cross-sectional base angle becomes larger than 75 °, the amount of lattice bending increases sharply, and the defect rate increases. Therefore, the cross-sectional base angle needs to be 75 ° or less.

In order to compare the performance of the lead storage battery according to the present invention with that of the conventional lead storage battery, each battery was made as follows and compared.

A conventional continuous cast lattice is made of Pb-Sb1.5
The composition was expressed as a mass%, and had a cross-sectional shape shown in FIG. A positive electrode plate was prepared using the continuous cast lattice as follows. First, 13% by mass of dilute sulfuric acid (specific gravity 1.26:
20 ° C.) and 12% by weight of water with respect to the lead powder to prepare a positive electrode active material paste. Next, 85 g of the positive electrode active material paste was filled in a continuous cast lattice having a cross-sectional shape shown in FIG. 3A, left to stand at 50 ° C. and 95% humidity for 18 hours, and then aged at 110 ° C. The resultant was left to stand for 2 hours and dried to form an unformed positive electrode plate. Next, 73 g of the negative electrode active material paste was filled in a current collector composed of a lattice, left to stand at 50 ° C. and 95% humidity for 18 hours for aging, and then left at 110 ° C. for 2 hours to dry. As a result, an unformed negative electrode plate was produced.

Next, seven unformed anode plates and eight unformed anode plates 8
Each of the electrode plates was formed by laminating the sheets via a bag-shaped separator covering the negative electrode. Then, after disposing each electrode plate group in a battery case, an electrolyte solution of dilute sulfuric acid having a specific gravity of 1.225 (20 ° C.) is injected into the battery case, and electricity is supplied at 9 A for 42 hours to produce a lead storage battery A. did.

The continuous cast lattice used in the lead storage battery of the present invention had a composition of 1.5 mass% of Pb-Sb, and had a sectional shape shown in FIG. Using this lattice, a lead storage battery B was prepared in the same procedure as in the conventional example.

Each of the completed conventional lead-acid battery and the lead-acid battery of the present invention was subjected to 560 Ω (250 m) at an ambient temperature of 40 ° C.
A) and left for 6 months. afterwards,
At an ambient temperature of 40 ° C., constant voltage charging was performed at a set voltage of 14.0 V and a limited current of 25 A. Then, a constant temperature bath 18 with an ambient temperature of -15 ° C
After leaving for a while, constant current discharge at 300 A,
At that time, the voltage at the 5th second, the voltage at the 30th second, and the discharge duration were measured. Table 1 shows the average values of these measurement results.

[0020]

[Table 1] As a result, in the lead storage battery B of the present invention example in which the inscribed circle of the lattice cross section was enlarged, the voltage at the 5th second, the voltage at the 30th second, and the duration of discharge were all superior to those of the conventional lead storage battery A. It can be seen that the characteristics have been improved.

After the discharge is completed, discharge at a temperature of 25.degree.
% Of electricity was charged at a constant current. Thereafter, these lead-acid batteries A and B were disassembled, an arbitrary positive electrode plate was taken out for each battery, a cross-section of the inner bone was observed, and the remaining lattice cross-sectional area was measured. Table 2 shows the average values of these measurement results.

[0022]

[Table 2] As a result, since the lead storage battery B of the example of the present invention in which the inscribed circle of the lattice cross section was enlarged had a larger residual lattice cross section than the lead storage battery A of the conventional example, it was found that the reduction in the cross sectional area due to corrosion was reduced. Was.

[0023]

According to the lead-acid battery of the present invention, since the cross-sectional shape of the inner bone of the continuous cast lattice is a trapezoid having an upper bottom on the mold side, the current collector can be formed even if each vertex is corroded. The cross-sectional area of the central portion, which functions as, becomes larger than the conventional one, and the battery characteristics can be improved.

In the lead-acid battery of the present invention, the trapezoid, which forms the cross-sectional shape of the inner bone of the continuous cast lattice, has a shape having the same sectional area and the maximum inscribed circle. Even if each vertex of the cross section is corroded, the cross-sectional area of the central portion functioning as a current collector is further increased, and the battery characteristics can be improved.

Further, in the lead storage battery of the present invention, the trapezoidal cross-sectional base angle which forms the cross-sectional shape of the inner bone of the continuous cast lattice is set to 75 °.
Since the following conditions are satisfied, a sharp increase in the amount of bending of the lattice body at the time of mold release can be prevented, and the defect rate can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing the specifications of the cross-sectional shape of an inner bone of a continuous cast lattice body of the present invention and a conventional example.

FIG. 2 is a diagram showing a relationship between a cross-sectional base angle of an inner bone of a lattice body and an average value of a lattice bending amount.

FIG. 3 is a diagram showing the specifications of the cross-sectional shape of the inner bone of the continuous cast lattice bodies of the present invention example and the conventional example.

Continuation of the front page (72) Inventor Miaki Machiyama 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo F-term in Shin-Kobe Electric Co., Ltd. 5H017 AA01 BB02 CC05

Claims (3)

[Claims] 1. A lead-acid battery using an electrode plate filled with an active material in a continuous cast lattice, wherein a cross-sectional shape of an inner bone of the continuous cast lattice is a trapezoid having an upper bottom on a mold side. Characteristic lead storage battery. 2. The lead-acid battery according to claim 1, wherein the trapezoid has the same cross-sectional area and a shape that maximizes an inscribed circle. 3. The lead-acid battery according to claim 1, wherein the trapezoid has a cross-sectional base angle of 75 ° or less.